OK. I remember that thread. The GXP bottom bracket does not require any spacers for that frame with the Apex crankset. I know spacers come with the bottom bracket, but they are for use with a MTB crankset on a 68mm bottom bracket. They are never used with a road crankset. I you have installed the cups with no spacers, then you just need to hit the drive side with a rubber mallet until is seats fully and you can tighten the non drive arm completely without any binding when you turn the cranks.
Note - sometimes the plastic drive side bushing from the old bottom bracket gets stuck on the spindle and needs to be pried off before you can install it in the new bottom bracket. If there is a black plastic thing on the drive side of the spindle, that needs to come off before it will fit in the new bottom bracket. I suspect that may be your problem, in this case.